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Upcoming Events
.	2010 Summer Professional Development School Internal Dosimetry 23 - 26 June 2010 Idaho State University, Pocatello, Idaho
.	International Conference on Radiation Protection in Medicine 1-3 September 2010 Varna, Bulgaria
.	2010 Meeting of the Air Monitoring Users Group 4-7 May 2010 Las Vegas, NV

20 March 2010

Atom

The smallest particle of an element that cannot be divided or broken up by chemical means. It consists of a central core of protons and neutrons, called the nucleus. Electrons revolve in orbits in the region surrounding the nucleus.